Rejected hormone therapy gave fewer cases of breast cancer

A reduction in recent years in the number of cases of breast cancer in women aged 50-59 years most probably depends on a decrease in the use of hormone replacement therapy to relieve problems associated with the menopause. A large Swedish study under the auspices of Karolinska Institutet confirms suspicions against the hormone therapy. The use of hormone replacement therapy (HRT) to relieve problems associated with the menopause reached a peak in Sweden in 1999 and then began to fall. The fall was accentuated after a large investigation in 2002 called the treatment into question. Several studies have shown that the number of cases of breast cancer fell suddenly in several countries, but it has not been clear whether the reduction in the use of HRT was the principal cause. Swedish scientists have now investigated trends in the incidence of breast cancer in Sweden between 1997 and 2007, a period during which the use of HRT fell dramatically. The percentage of women aged 50-59 years who used HRT fell from a peak of 36% in 1999 to 27% in 2002, and to 9% in 2007.